Investigation of the Bifurcation Process in the RL Diode Circuit by Employing Mathieu and Hill Equations

1997 ◽  
Vol 07 (07) ◽  
pp. 1665-1672 ◽  
Author(s):  
G. Sarafian ◽  
B. Z. Kaplan

The work deals with the dynamic processes of the RL diode circuit at the bifurcation points. It is shown, that just at the first bifurcation point (slightly beyond it) the circuit dynamics can be modeled by the Mathieu equation. Furthermore, the role of the voltage source there is not in imposing forcing function to the system equation. It has been discovered that the role of the source is that of a pumping source in the parametric sense. Hence, the resonator behaves at the bifurcation point as if it were a resonator, whose reactor is periodically time-varying. Further investigations of the dynamics at higher bifurcation points reveal that a similar mechanism is repeated and the processes there can be modeled by the Hill equation (which is a generalized version of the Mathieu equation). The theoretical investigation for the first bifurcation point is supported by experiments. Practical half-tone generators are shown to be closely related to the RL diode circuit.

2016 ◽  
Vol 5 (1) ◽  
Author(s):  
Amaldass M. ◽  
Neema Gnanadev

Pandit Nehru affirmed that women development/ empowerment is the basis for the substantial growth of a family, a village, or a nation. Development/upliftment of women is an essential ingredient of human development. Entrepreneurship development among the rural women folk would strengthen the village economy and promote regional development. The women entrepreneurs have proved that there is a source of immense untapped power in the womanhood of India (Margaret, 1992). Women undoubtedly are the backbone of the socio-economic-cultural aspects in the hill scenario. The subsistence agriculture which leads to low and unstable incomes, which in turn lead to a sizeable out-migration of male members that leads to only women headed families behind, and the role of women in the household economy becomes more important (Rawat, 2004). In the midst of limited opportunities, tough terrains and lack of resources, the contribution of women entrepreneurs to the society is enormous. An attempt was made to highlight the strategies and development aspects of rural women entrepreneurs in Almora district. Entrepreneurs who are engaged in self-employment and innovative entrepreneurial activities were selected for the study. A total of 50 samples were selected and the data were collected through interviews and focus groups. The study reveals various aspects related to rural women entrepreneurship and constraints that need attention so to empower women in their efforts toward integral development.


2021 ◽  
Vol 13 (9) ◽  
pp. 4898
Author(s):  
Andrzej Tucki ◽  
Korneliusz Pylak

Regional inequalities are a major concern for governments and policymakers. There is no doubt that tourism impacts the reduction of inequalities, but this impact is not entirely clear. We consider this ambiguity to be related to both the level of study and type of accommodation. In the present study, we examine the inequality level measured by the Gini coefficient in 108 municipalities of the peripheral region of northeastern Poland from 2009 to 2018. We employ a directional spillover index to measure the impact of two accommodation types on tax incomes per capita. The empirical results indicate that collective accommodation-based tourism only reduced inequality during the financial crisis, while individual accommodation-based tourism started to reduce inequality from 2014, when Russian sanctions hit local agriculture and businesses. These results indicate that the role of accommodation types is time-varying and evident in measuring economic distress during and after shocks.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Martin L. Pall

Abstract Millimeter wave (MM-wave) electromagnetic fields (EMFs) are predicted to not produce penetrating effects in the body. The electric but not magnetic part of MM-EMFs are almost completely absorbed within the outer 1 mm of the body. Rodents are reported to have penetrating MM-wave impacts on the brain, the myocardium, liver, kidney and bone marrow. MM-waves produce electromagnetic sensitivity-like changes in rodent, frog and skate tissues. In humans, MM-waves have penetrating effects including impacts on the brain, producing EEG changes and other neurological/neuropsychiatric changes, increases in apparent electromagnetic hypersensitivity and produce changes on ulcers and cardiac activity. This review focuses on several issues required to understand penetrating effects of MM-waves and microwaves: 1. Electronically generated EMFs are coherent, producing much higher electrical and magnetic forces then do natural incoherent EMFs. 2. The fixed relationship between electrical and magnetic fields found in EMFs in a vacuum or highly permeable medium such as air, predicted by Maxwell’s equations, breaks down in other materials. Specifically, MM-wave electrical fields are almost completely absorbed in the outer 1 mm of the body due to the high dielectric constant of biological aqueous phases. However, the magnetic fields are very highly penetrating. 3. Time-varying magnetic fields have central roles in producing highly penetrating effects. The primary mechanism of EMF action is voltage-gated calcium channel (VGCC) activation with the EMFs acting via their forces on the voltage sensor, rather than by depolarization of the plasma membrane. Two distinct mechanisms, an indirect and a direct mechanism, are consistent with and predicted by the physics, to explain penetrating MM-wave VGCC activation via the voltage sensor. Time-varying coherent magnetic fields, as predicted by the Maxwell–Faraday version of Faraday’s law of induction, can put forces on ions dissolved in aqueous phases deep within the body, regenerating coherent electric fields which activate the VGCC voltage sensor. In addition, time-varying magnetic fields can directly put forces on the 20 charges in the VGCC voltage sensor. There are three very important findings here which are rarely recognized in the EMF scientific literature: coherence of electronically generated EMFs; the key role of time-varying magnetic fields in generating highly penetrating effects; the key role of both modulating and pure EMF pulses in greatly increasing very short term high level time-variation of magnetic and electric fields. It is probable that genuine safety guidelines must keep nanosecond timescale-variation of coherent electric and magnetic fields below some maximum level in order to produce genuine safety. These findings have important implications with regard to 5G radiation.


2021 ◽  
pp. 096834452199586
Author(s):  
James Shelley

Despite the vast academic and popular interest in the Dieppe raid of 19 August 1942, there remains a curious oversight of the German side of the story. This contribution interrogates German sources in order to explore the Dieppe air battle and its consequences from the perspective of the German armed forces. The paper ultimately demonstrates that the Germans learnt much about the role of air power in coastal defence from their experiences at Dieppe, but that the implementation of those lessons was lacking.


2016 ◽  
Vol 8 (1) ◽  
pp. 57-82 ◽  
Author(s):  
Francesc Dilmé ◽  
Fei Li

We study the role of dropout risk in dynamic signaling. A seller privately knows the quality of an indivisible good and decides when to trade. In each period, he may draw a dropout shock that forces him to trade immediately. To avoid costly delay, the seller with a low-quality good voluntarily pools with early dropouts, implying that the expected quality of the good increases over time. We characterize the time-varying equilibrium trading dynamics. It is demonstrated that the maximum equilibrium delay of trade is decreasing in the initial belief that the good is of high quality. (JEL C73, D82, D83)


2014 ◽  
Vol 19 (6) ◽  
pp. 1294-1308 ◽  
Author(s):  
Nicola Acocella ◽  
Giovanni Di Bartolomeo ◽  
Patrizio Tirelli

This paper offers a reinterpretation of the Fed's time-varying implicit inflation target, based on two considerations. The first is that the need to alleviate the burden of distortionary taxation may justify the choice of a positive inflation rate. The second is based on compelling evidence that the degree of price and wage indexation falls with trend inflation. In fact, we find that a proper characterization of the joint evolution of fiscal variables and nominal rigidities has a strong impact on the Ramsey optimal policies, implying optimal inflation dynamics that are consistent with the observed evolution of U.S. trend inflation. By contrast, tax policies have been too lax, especially at the time of the controversial Bush tax cuts.


2021 ◽  
Author(s):  
Doriane Intungane

The recent financial crisis started a global debate on the role of financial policies, which led to financial system reforms in many countries. These reforms mainly consisted of increasing the usage of macroprudential policies. This dissertation seeks to understand whether macroprudential policies in financially integrated countries reduced their vulnerability to the impact of external shocks. Chapter 2 empirically examines the impact of macroprudential policies on cross-border bilateral credit growth. Capital requirements and loan-to-value (LTV) ratios, in 15 lending countries and 34 borrowing countries between 2000 and 2014, are used in the analysis. The results show that in some countries, the increase of capital requirements is not effective in reducing international credit flows during periods of financial vulnerability. The impact of tightening LTV ratios is more heterogeneous across countries because LTV ratios are mainly used in the housing sector and not all countries change their LTV ratio frequently. Hence, cooperation across countries is necessary but also countries should make sure that the change of macroprudential policies targeting lenders and those targeting borrowers complement each other to avoid international leakages. Chapter 3 analyzes issues related to the international spillover of macroprudential policies through international banking activities using a two-country dynamic stochastic general equilibrium model with heterogeneous and time-varying macroprudential policies. The results show that a combination of capital requirements and LTV ratios is effective in reducing credit growth despite the existence of cross-border banking activities and heterogeneous implementation of capital requirements across countries. In addition, international coordination of capital requirements is also effective in reducing credit growth but less effective than a combination of capital requirements and LTV ratios. Chapter 4 focuses on the role of countercyclical LTV ratios in reducing transmission of shocks when international investors, holding domestic and foreign assets, face collateral constraint. Using a two-country dynamic stochastic general equilibrium model, the analysis demonstrates that time-varying LTV ratios can reduce the transmission of shocks.


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